Effect of Adenosine Diphosphate on Adhesiveness of Platelets in vitro and in vivo

ADENOSINE diphosphate (ADP) is known to cause reversible aggregation of human and animal platelets in vitro1–4. Hellem et al.5 used a column of glass beads6 to determine an increase, within certain limits, in the adhesiveness of platelets in response to ADP. Born and Cross7 and Chin8 have also shown that intravascular injection of ADP produces a rapid and transient decrease in the number of circulating platelets, which is probably caused by the adhesion of platelets to the endothelium and the aggregation of platelets leading to intravascular trapping7. Silver and Stehbens9 have used ear chambers to demonstrate the intravascular aggregation of platelets in rabbits caused by intravenous infusion of ADP.